JPS61231002A - Manufacture of free radical initiation addition polymer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the free radical initiated polymerization of polymerizable ethylenically unsaturated septamers, particularly in the presence of hydrogen peroxide.

Conventional techniques and free-radical initiated polymerizations of polymerizable ethylenically unsaturated septamers in organic media have been carried out using so-called oil-soluble free radical initiators, such as azo compounds or organic peroxides which are soluble in organic media. Usually done. Hydrogen peroxide is a well-known free radical initiator for the addition polymerization of ethylenically unsaturated heptamers. However, hydrogen peroxide is primarily used in aqueous emulsion polymerizations and is not well known for use in non-aqueous polymerizations using oil-soluble free radical initiators as described above. However, these materials are relatively expensive;
Also, certain azo compounds cannot be used due to health and safety concerns.

However, the use of aqueous hydrogen peroxide as a free radical initiator for non-aqueous polymerizations is known in the art. U.S. Patent Nos. 3,370,050 and 3.366,
No. 605 discloses that copolymers of hydroxyalkyl esters of unsaturated acids and copolymers of ethylenically unsaturated amides can be formed using aqueous hydrogen peroxide as a free radical initiator for addition polymerization. Disclosed. According to these patents, an aqueous hydrogen peroxide solution is added to the reaction zone together with a polymerizable hexamer and the reaction mixture is heated to reflux to effect polymerization. Water added with hydrogen peroxide is removed from the system during a later stage or after the polymerization is complete. Although this method of using an aqueous hydrogen peroxide solution is said to be effective for producing the copolymers described in the above-mentioned US patent specification, these copolymers have relatively large molecular weights. It has been found that this use of aqueous hydrogen peroxide is not particularly effective when producing low molecular weight acrylic polymers having a molecular weight of 4000 or less.

The low molecular weight and therefore low viscosity of these polymers allows them to be formulated into coating compositions that use little organic solvents in accordance with environmental regulations regarding solvent inclusion in coating compositions, and are therefore preferred in the coatings industry. The importance of polymers is increasing. It has been found that carrying out the reaction by reflux in the presence of water limits the reaction temperatures that can be achieved and that higher reaction temperatures are preferred when producing small molecule cap polymers. Furthermore, the presence of an aqueous free radical initiator in the reaction medium results in heterophase polymerization. That is, polymerization occurs in both the aqueous and organic phases, resulting in the preparation of polymers with relatively broad molecular weight distributions and thus undesirably high viscosities.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a method for preparing free radical initiated addition polymers by polymerizing a polymerizable ethylenically unsaturated monomer component in the presence of a hydrogen peroxide solution. The hydrogen peroxide solution is added incrementally to the monomer components to be polymerized during the polymerization process, and at the same time the low boiling organic solvent and water are removed while adding the hydrogen peroxide solution.

The process of the present invention allows relatively high reaction temperatures to be achieved using high boiling solvents and to avoid heterogeneous-phase polymerization conditions. The process of the invention results in low molecular weight acrylic polymers having a relatively narrow molecular weight distribution. Furthermore, the use of hydrogen peroxide ensures that hydroxyl groups are attached to many polymer molecules. In many cases, even when relatively high proportions of hydroxyl-containing acrylic monomers are used, some molecules in the resulting polymer molecule distribution contain insufficient or no hydroxyl groups. This is insufficient when the polymer is subsequently cured with a curing agent such as an aminoplast or incyanate, thus leading to defects and defects in the cured film.

In addition to the prior art described above, Japanese Patent Application Laid-Open No. 76045/1982 discloses the use of an aqueous hydrogen peroxide solution in the production of an acrylic polymer with a relatively low molecular weight (number average molecular weight: 500-5000) prepared in an organic solvent. Disclosed in the official gazette. In order to increase the polymerization temperature, the reaction is carried out under high pressure in an autoclave. This method is both hazardous and less economical than the method of the present invention, which does not require the use of high pressure and expensive high pressure equipment.

JP-A-69206/1983 discloses the use of aqueous hydrogen peroxide solutions for the production of acrylic polymers in organic solutions. In this method, an aqueous hydrogen peroxide solution is first dissolved in an acetate ester, such as butylacetate, and water is removed from the solution by azeotropic distillation. An organic solution of hydrogen peroxide is then used in the polymerization. Compared to the method of the present invention, this method is limited in its selection of organic solvents and requires cumbersome pretreatments of the aqueous hydrogen peroxide solution, ie, dissolution and distillation, before use.

Furthermore, the solubility of aqueous hydrogen peroxide solution in acetate ester is also limited. In contrast, according to the method of the present invention,
Hydrogen peroxide can be used directly and its solubility in organic solvents is not limited.

The process of the invention involves the addition polymerization of polymerizable ethylenically unsaturated monomers which polymerize through ethylenically unsaturated groups and where the polymerization is initiated by free radicals. The ethylenically unsaturated monomer component includes one or more commonly a mixture of ethylenically unsaturated monomers. Suitable monomers include olefinic hydrocarbons, particularly monomers having a CH2=C= structure, vinylidene monomers,
Acrylic monomers are included, including vinyl monomers and methacrylic monomers. Suitable monomers include: ethylene, furopylene, 1,3-phtadiene, styrene and vinyltoluene; halogenated monoolefinic hydrocarbons such as chlorostyrene; a! Unsaturated esters of acids, such as vinyl acetate and vinyl butyrate; esters of unsaturated acids, such as methyl methacrylate,
Ethyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate and dimethyl maleate; unsaturated acids, such as acrylic acid, methacrylic acid and maleic acid; unsaturated compounds containing hydrocylic groups, such as hydroxylethyl methacrylate, hydroquinpropyl methacrylate, Allyl alcohol and bis(hydroxyethyl) maleate; unsaturated compounds containing epoxy groups, such as glycidyl methacrylate; unsaturated monomers containing amide groups 1, such as acrylamide, methacrylamide and alkoxy-substituted amides, such as N-butoxymethylacrylamide and N-ethoxymethylmethacrylate Amides; Nitriles such as acrylonitrile and methacrylate.

For use as a thermosetting resin binder in coating compositions, the resulting polymer must contain active hydrogen that is reactive with the curing agent, such as an aminoplast or a polyisocyanate. In the case of reaction with aminoplasts, the active hydrogens are usually those contained in hydroxyl groups and/or carboxylic acids; in the case of reactions with polyisocyanates, the active hydrogens are usually contained in hydroxyl groups and/or amines. It is something. Although hydroxyl groups can be introduced into the terminal positions of the polymer molecule by using hydrogen peroxide as a free radical initiator, the monomer components are compatible.
ble) It is preferred to contain at least 1 to 50% by weight of active hydrogen-containing unsaturated monomers, based on the total weight of the monomers.

Preferably, the ethylenically unsaturated monomer is a monomer-soluble organic diluent with a high boiling point, i.e. a boiling point of at least 125°C, preferably at least 140°C, at atmospheric pressure.
, usually in an organic diluent at 140-200°C. Examples of suitable solvents include: ketones such as methyl ethyl ketone, methyl imbutyl ketone; esters such as im butyl isobutyrate,
2-Ethylhexyl acetate and Etsukunun Co., Ltd. (E
xxon Company) to Ext.
ATE) commercially available high-boiling ester mixtures as commercially available as solvents; hydrocarbons such as cumene, xylene,
Butylbenzene and aromatic (
aromatic) Zo.

Glycol ethers, such as 2-butoxycetanol and the monobutyl ether of diethylene glycol. Also,
Low molecular weight polymers, such as polyesters having a number average molecular weight of less than 3000, usually from 500 to 1000, alone or in mixtures with any of the above-mentioned high-boiling organic solvents may be used as organic diluents. Further, a relatively low boiling point solvent, that is, a solvent having a boiling point of 100° C. or lower, such as impropatol or methyl ethyl ketone, may be present in the high boiling point organic solvent. A preferred diluent is a ketone such as methyl amyl ketone. This is because these solvents result in lower molecular weight products than when using other diluents. The amount of organic diluent used in the practice of this invention is not particularly critical, but is typically about 2-20% by weight of the reaction medium, based on the total weight of monomer charge and organic diluent. Although not preferred, the polymerization may be a bulk polymerization.

The hydrogen peroxide solution used in the practice of the present invention is preferably an aqueous solution such as is commercially available. Highly concentrated solutions, i.e. 70-90
Weight percent solutions may be used, but lower concentration solutions, i.e., about 2% by weight, may be used.
It is more difficult to handle than a 0-50% by weight solution. Organic solutions of hydrogen peroxide, for example solutions using low boiling organic solvents such as ethyl acetate, may be used, but these are not preferred.

The amount of hydrogen peroxide used may be as little as 0.1% by weight, but is preferably about 2-20% by weight. The weight percentages in this case are in terms of hydrogen peroxide and are based on the total weight of the polymerizable ethylenically unsaturated monomer. Hydrogen peroxide is preferably used in relatively large amounts, ie 5-20% by weight, as this results in low molecular weight polymers.

In a preferred embodiment of the polymerization, the organic solvent and optional monomer components and a portion of the hydrogen peroxide solution are heated to reflux. The monomer components and the remainder of the hydrogen peroxide solution are slowly added into the reaction medium, while water and low-boiling organic solvents are continuously removed from the reaction zone, for example by distillation. In other words, the hydrogen peroxide solution is added incrementally to the polymerized additive during the polymerization process, and water and low boiling organic solvents are removed while adding the hydrogen peroxide solution. In this case, the water associated with hydrogen peroxide, i.e., water from the decomposition of hydrogen peroxide and water as an aqueous solvent when using an aqueous hydrogen peroxide solution, is used to carry out the reaction at a high temperature, i.e. at approximately the boiling point of the remaining high-boiling organic solvent. It is removed as soon as it is added to the reaction zone.

The reaction time is the time during which the heptamer is substantially completely converted to polymer and is actually dependent on the location and temperature of the catalyst used. Preferred polymerization temperatures are at least 140°C, usually about 140-200°C. The reaction time at such temperatures is usually about 4 to 8 hours.

As mentioned above, the process of the present invention uses low molecular weight polymers, i.e. polymers with a number average molecular weight not exceeding 8,000, preferably 4,000 or less, usually about 4,000 to 100
It is particularly useful in producing polymers with a molecular weight of 0, but may also be used in producing higher molecular weight polymers. The molecular distribution or polydispersity of preferred low molecular weight polymers (
The polydispersity (weight average molecular weight divided by number average molecular weight) is usually relatively narrow, less than 5, preferably about 2.5 to 3.2. Molecular weight is determined by gel permeation chromatography using polystyrene standards.

Due to the use of hydrogen peroxide, a low molecular weight polymer is obtained, and each polymer molecule is believed to have a hydroxyl group attached to it. The polymers may be used as resin binders for coating compositions, especially vinelid-type coating compositions, together with suitable crosslinkers, such as aminoplasts or polyisocyanates.

The following examples of the invention relate to a process for making low molecular weight acrylic polymers in organic diluents using aqueous hydrogen peroxide as the free radical initiator.

EXAMPLES The following examples illustrate the use of aqueous hydrogen peroxide as a free radical initiator for the organic solution polymerization of heavy metal capable ethylenically unsaturated monomer mixtures. Adding an aqueous hydrogen peroxide solution incrementally to the superpolymerized mixture during the polymerization process and removing water associated with the aqueous solution by azeotropic distillation while adding the aqueous hydrogen peroxide solution while maintaining the polymerization temperature at at least 140°C. do.

These examples concern the polymerization of various monomer mixtures, varying the concentration and amount of organic solvent and hydrogen peroxide used to affect the color and molecular weight of the resulting polymer.

Example Work In this example, 40% hydroxypropyl acrylate, 20% styrene, 19% butyl acrylate.
A monomer mixture containing 18.5% butyl methacrylate, 2 acrylic acid and 0.5% methyl methacrylate was dissolved in a 50% aqueous hydrogen peroxide solution (50% aqueous hydrogen peroxide) in an aromatic solvent.
% active) (approximately 8.8% by weight based on total weight of monomers)
of H2O2). The reaction was carried out using the following formulation.

A-1001) 1200.01
) An aromatic mixed solvent with a boiling point of 160° C., commercially available as Aromatic 100 from Exxon.

Ingredients Overlapping part (g) Hydroxypropyl acrylate 720.0 Styrene
360.0 Butyl acrylate 342.0 Butyl methacrylate
333.0 Acrylic acid
36.0 Methyl methacrylate
9.0 Feed B 50% by weight hydrogen peroxide aqueous solution 316.82
The kettle charge was placed in a 51-reaction flask equipped with an addition funnel, thermometer, condenser, and Dean-Stark wrap and heated to reflux. Feeds A and B at a reaction temperature of 15
They were added simultaneously over a period of 5 hours while being maintained at 3-158°C, while water was continuously removed by azeotropic distillation. After the addition of feeds A and B was complete, the reaction mixture was maintained at 158° C. for 30 minutes to complete the reaction. The solids content of the final reaction product (measured for 2 hours at 110°C) is 60%, the Gardner-Holdt viscosity is x1, the acid number is 9.4, and the color value is
ue ) (Gardner color value) was 1. The peak molecular weight (Mz) determined by gel permeation chromatography using polystyrene standards was 3682.
, number average molecular weight (Mn) is 3682 and polydispersity is 4
．． It was 2.

Example ■ A polymer similar to the example was prepared using imbutyl isobutyrate in place of Aromatic 100. The reaction was carried out using the following formulation.

Inbutyl isobutyrate 1200 Feed A Hydroxypropyl acrylate 720 Styrene 360 Butyl acrylate 342 Butyl methacrylate 333 Acrylic acid
36 methyl methacrylate
9 Feed B Component Overlapping part (g) 50% by weight
Hydrogen peroxide aqueous solution 316.8 (8.8% H20
□) The kettle charge was placed in a 51-reaction flask equipped with a flask-like apparatus as used in Example 1 and heated to reflux at 150°C. Feeds A and B at a reaction temperature of about 145
℃ and were added simultaneously and continuously over a period of 5 hours, while water was continuously removed by azeotropic distillation. Feed A
After the addition of B and B was completed, the reaction mixture was maintained at 146° C. for 1 hour to complete the reaction. The final reaction product had a solids content of 59.8%, a Gardner-Holdt viscosity of v1, an acid number of 18.9 and a color value of 1.

The resulting polymer had an Mz of 8111, an Mn of 3431 and a polydispersity of 3.3, as determined by gel permeation chromatography using polystyrene standards.

(Hereinafter, blank space) Example ■ Using methyl amyl ketone as an organic solvent, Example I
Polymers similar to those obtained in (1) and (2) were prepared. The reaction was carried out using the following formulation.

Methyl amyl ketone 1200 Feed A Ingredients Part by weight tg > Hydroxypropyl acrylate 720 Styrene
360 butyl acrylate
342 Butyl methacrylate
333 acrylic acid
36 methyl methacrylate
9 Feed B Ingredients Part by weight tg) 50% by weight hydrogen peroxide aqueous solution 316.8 (8.8%
H20°] A 51-reaction flask equipped as described in Example 1 was charged with a kettle charge and 10% by weight of Feed B, and the reaction mixture was heated to reflux at 130°C. The remainder of Feed A and Feed B was heated to a reaction temperature of 142 to 1
They were added simultaneously over a period of 5 hours while being maintained at 47°C, and water was continuously removed by azeotropic distillation. Feed A
After addition of B and B, the reaction mixture was heated to 145-150°C.
It was maintained for 30 minutes. The solids content of the reaction mixture is 61
．． 5%, Gardner-Holdt viscosity was E+, acid number was 26 and color value was 1. The polymer's Mz was 2473, Mn 1093 and polydispersity 2.31 as determined by gel permeation chromatography using polystyrene standards.

Example 2 A high molecular weight product was prepared in a similar reaction to Example 2, except that 4.5% by weight hydrogen peroxide, based on the weight of the 7-mer, was used in the polymerization. The reaction was carried out using the following formulation.

Kettle Charge Ingredients Parts by weight + gl Methyl amyl ketone 1200 Feed A Ingredients Parts by weight tg) Hydroxypropyl acrylate 720 Styrene
360 butyl acrylate
342 Butyl methacrylate
333 acrylic acid
36 methyl methacrylate 9
Feed B Ingredients Weight part 1g + 50 weight - Hydrogen peroxide aqueous solution 162 (4.5% H2
O2) 5I equipped with the equipment described in Example 1! - A kettle charge was placed in the reaction flask and heated to reflux.

Feeds A and B were added simultaneously over a period of 5 hours while maintaining the reaction temperature at 147-150°C, and water was continuously removed by azeotropic distillation.

After the addition of feeds A and B is complete, the reaction mixture is heated to 150 ml.
The reaction was completed by maintaining the temperature at -153°C for about 90 minutes. The solids content of the reaction mixture was 64.1%, the Gardner-Holdt viscosity was I-J, the acid number was 12.5 and the color value was 1.
Met. Determined by gel permeation chromatography using polystyrene standards, TaMz is 38
62, Mn was 1806 and polydispersity was 3.01.

Example V This example is similar to Example II except that a 70% by weight aqueous hydrogen peroxide solution (I based on monomer weight (2e4 degrees = 3% by weight) is used. The reaction is carried out using the following formulation. This was done by

Methyl amyl ketone 1200 Feed A Hydroxypropyl acrylate 720 Styrene 360 Butyl acrylate 342 Butyl methacrylate
333 acrylic acid
36 methyl methacrylate
9 Feed B Ingredients Weight part 1g) 70 Weight - Hydrogen peroxide aqueous solution 77.1 (3% H2°2
) A kettle charge 5e- equipped with the equipment described in Example I.
The mixture was placed in a reaction flask and heated to reflux at 150°C. Feeds A and B were added simultaneously over a period of 5 hours while maintaining the reaction temperature at 150-152°C, while water was continuously removed by azeotropic distillation. After the addition of Feeds A and B was complete, the reaction mixture was maintained at 155° C. for approximately 1 hour to complete the reaction. The solids content of the reaction mixture was 63.
2, the Gardner-Holdt viscosity was K, the acid number was 11.5 and the color value was 1. The resulting polymer has an Mz of 3862 and an Mn of 1943, determined by gel permeation chromatography using polystyrene standards.
and polydispersity was 2.74.

Example V1 This example is based on the weight of monomer used.
Example similar to Example 2, except that % by weight of hydrogen peroxide is used to obtain a high molecular weight product.

The reaction was carried out using the following formulation.

Methyl amyl ketone 1200 Feed A Hydroxypropyl acrylate 720 Styrene 360 Butyl acrylate 342 Butyl methacrylate
333 acrylic acid
36 methyl methacrylate
9 Feed B (2,25% H202) 51 with a kettle charger equipped with the equipment described in the example work!
- The mixture was placed in a reaction flask and heated to reflux at 150°C.

Feeds A and B were added simultaneously over a 5 hour period while maintaining the reaction temperature at 147-155°C. Feed A
After the addition of B and B was completed, the reaction mixture was held at 155° C. for 2 hours to complete the reaction. The solids content of the reaction mixture was 63.0%, the Gardner-Holdt viscosity was Jl, the acid number was 11.6 and the color value was 2. The resulting polymer had an Mz of 4062, a Mn of 1900 and a polydispersity of 2.82 as determined by gel permeation chromatography using polystyrene standards.

Example vn This example uses 1.5% by weight hydrogen peroxide based on the weight of monomers used to prepare a higher molecular weight polymer.
This is a similar example to Example VI except for the pear shape. The reaction was carried out using the following formulation.

Methyl amyl ketone 1200 Feed A Ingredients Part by weight tg) Hydroxypropyl acrylate 720.0 Styrene
360.0 Butyl acrylate 342.0 Butyl methacrylate 333.0 Acrylic acid
36.0 Methyl methacrylate
9.0 Feed B Ingredients Weight part 1g 150% by weight hydrogen peroxide aqueous solution 81 (1.5% H2O
2) Charge the kettle with the equipment described in Example 1.
1! - The mixture was placed in a reaction flask and heated to reflux at 150°C. Feed A and B, reaction temperature 150-155
were added simultaneously over a period of approximately 5 hours while maintaining the temperature at °C, while
Water was continuously removed by azeotropic distillation. After the addition of Feeds A and B was complete, the reaction mixture was maintained at 153-154° C. for approximately 2 hours to complete the reaction. The solids content of the reaction mixture was 62.9%, and the Gardner-Holdt viscosity was o1
The acid value was 11.3 and the color value was 2. The Mz of the resulting polymer determined by gel permeation chromatography using polystyrene standards is 7125;
Mn was 2765 and polydispersity was 3.77.

Example via This example uses a 35% by weight aqueous hydrogen peroxide solution (7% by weight).
Example V except that a higher molecular weight product was prepared using a concentration of hydrogen peroxide - 5% by weight based on the weight of
This is an example similar to (2). The reaction was carried out using the following formulation.

Kettle charge component Weight part Tg) Methyl amyl ketone 1200 Feed A Ingredient Weight part Tg) Hydroxypropyl acrylate 720 Styrene
360 butyl acrylate
342 Butyl methacrylate
333 acrylic acid
36 Methyl methacrylate 9 Feed B Ingredients Part by weight 1 g) 35 Weight - Hydrogen peroxide aqueous solution 26 (0.5% H2O
2) The kettle charger is equipped with the equipment described in the example work.
1-The mixture was placed in a reaction flask and heated to reflux. Feeds A and B were added simultaneously over a period of approximately 5 hours while maintaining the reaction temperature at 147-149°C, and water was continuously removed by azeotropic distillation. After the addition of Feeds A and B was complete, the reaction mixture was heated at about 150° C. for 2 hours to complete the reaction. The solids content of the reaction mixture is 60.8%
, Gardner-Holdt viscosity was S, acid number was 10.6 and color value was 2. The resulting polymer had an Mz of 11630, a Mn of 4332 and a polydispersity of 3.5 as determined by gel permeation chromatography using styrene standards.

Example ■ 50% by weight of hydroxyethyl methacrylate and 2-
A reaction similar to Example In was carried out except that a monomer containing 50% by weight of ethylhexyl methacrylate was used. The reaction was carried out using the following formulation.

Methyl amyl ketone 1200 Feed A Hydroxyethyl methacrylate 900 2-ethylhexyl methacrylate 900 Feed B 50% by weight aqueous hydrogen peroxide solution 316.8 (8
, 8% H2O2) 51! with a kettle charger equipped with the apparatus described in Example I!
- The mixture was placed in a reaction flask and heated to reflux at 150°C.

Feeds A and B were added simultaneously over a period of about 5 hours while maintaining the reaction temperature at 150-157° C., and water was continuously removed by azeotropic distillation. After the addition of feeds A and B is complete, the reaction mixture is heated to about 150-155°C.
Time was maintained. The solids content of the reaction mixture was 59%, the Gardner-Boldt viscosity was A, the acid number was 12.5, and the color value was 2. The resulting polymer had an Mz of 1016, an Mn of 757 and a polydispersity of 1.73 as determined by gel permeation chromatography using polystyrene standards.

Example X This example is similar to Example V except that a mixture of methyl amyl ketone and low molecular weight polyester is used as the solvent. Monomer charge: 35% by weight of 2-ethylhexyl acrylate, 34.5% by weight of styrene.
30% by weight of hydroxyethyl methacrylate and 0.5% by weight of methyl methacrylate. The concentration of hydrogen peroxide was 0.3% by weight based on the weight of monomer. The reaction was carried out using the following formulation.

Polyester υ 300 methyl amyl ketone 300 υ 300.7 parts by weight of 1,6-hexanediol, 183.1 parts by weight of hexahydrophthalic anhydride and 115.8 parts by weight of adipic acid were added to 62.9 parts by weight of methyl isobutyl ketone. A low molecular weight polyester prepared by condensation in a bed.

In this reaction, butyl stannate (butyl 5tan-n
oicacid) and 0.31 parts by weight of triphenyl phosphate were used as catalysts. The polyester had an acid number of 8.14, a hydroxyl number of 107.4, a solids content of 88.5%, and a Gardner-Holdt viscosity of [J-V].

Feed A Ingredients Weight parts tg) 2-ethylhexyl acrylate 315 styrene
310.5 Hydroxyethyl methacrylate 270.0 Methyl methacrylate
4.5 Feed B Ingredients Parts by weight (g150 weight - Hydrogen peroxide aqueous solution i 54.0 (0.3%
H20°) A kettle charge was equipped with the equipment described in Example I f:, 5
I! - The mixture was placed in a reaction flask and heated to reflux at 148°C. Feeds A and B at a reaction temperature of 148-156
They were simultaneously added over a period of about 3 hours while maintaining the temperature at ℃,
Water was removed coupled by azeotropic distillation. After the addition of feeds A and B was completed, the reaction mixture was held at 165-169° C. for about 1 hour to complete the reaction. The solids content of the reaction mixture was 79.1%, the acid number was 7.4, the Gardner-Holdt viscosity was 2 and the color value was 2.

Claims (1)

[Scope of Claims] 1. A method for producing a free radical-initiated addition polymer by polymerizing a polymerizable ethylenically unsaturated monomer component in the presence of a hydrogen peroxide solution, which comprises adding a hydrogen peroxide solution during the polymerization process. Preparation of a free radical-initiated addition polymer, characterized in that a low-boiling organic solvent and water are added incrementally to the polymerizable monomer component and, at the same time, a low-boiling organic solvent and water are removed from the polymerizable monomer while adding a hydrogen peroxide solution. Method. 2. The method according to item 1, wherein the hydrogen peroxide solution is an aqueous solution. 3. The method according to item 1, wherein the polymerization is carried out at ambient pressure. 4. The method of item 1, wherein the polymerizable ethylenically unsaturated monomer component is dissolved in an organic solvent. 5. The method according to item 1, wherein the polymerizable ethylenically unsaturated monomer component is a hydroxyl group-containing monomer. 6. The method according to item 5, wherein the hydroxyl group-containing monomer contains at least 10% by weight of an ethylenically unsaturated monomer component. 7. The method according to item 1, wherein the polymerizable ethylenically unsaturated monomer component contains a carboxylic acid group-containing monomer. 8. The method of paragraph 1, wherein the addition polymer has a number average molecular weight not exceeding 8,000. 9. The method according to item 8, wherein the addition polymer has a number average molecular weight of 1,000 to 4,000. 10. The first step in which the polymerization is carried out at a temperature of at least 140°C.
The method described in section. 11. The method according to paragraph 4, wherein the organic solvent is selected from the group consisting of aromatic hydrocarbons, ketones and esters. 12. The method according to item 1, wherein the water and the low-boiling organic solvent are removed by distillation. 13. The method of item 2, wherein the amount of hydrogen peroxide added is about 0.2 to 20% by weight based on the total weight of the polymerizable monomer components. 14. A method for producing a free radical-initiated addition polymer by polymerizing a polymerizable ethylenically unsaturated monomer component dissolved in an organic solvent in the presence of an aqueous hydrogen peroxide solution, in which the aqueous hydrogen peroxide solution is added during the polymerization process. 1. A method for producing a free radical-initiated addition polymer, which comprises incrementally adding water to a polymerizable monomer component capable of polymerization and simultaneously removing water from the polymerizable monomer component while adding an aqueous hydrogen peroxide solution. 15. The method according to item 14, wherein the polymerization is carried out at a temperature of 140°C or higher. 16. The method according to paragraph 14, wherein the water is removed by distillation. 17. The method of item 1, wherein the amount of hydrogen peroxide added is about 0.2 to 20% by weight based on the total weight of the polymerizable monomer components. 18. The method according to paragraph 14, wherein the polymerization is carried out at ambient pressure.